Beach volleyballers?

Question

Why are they always pointing by their butts? Are they sending signals? Keeping track of points? why why why!

Answer 1

They are sending signals to their partner to show what sort of play they intend to make.

Those signals are made behind them, on back or butt to avoid the opposite players of seeing them.

Most commonly the signals are given with both hands by the serving player's partner before the serve, with each hand referring to the type of block the signaler will put up against an attack from the corresponding side of the court.

An open hand means the player will not attempt a block, one finger means the player will attempt to block an opponent's spike down the line, two fingers means the player will attempt to block an opponent's spike into the angle, and a closed fist means the player will block "ball," deciding where to set the block based on the set and on the opponent's approach and arm-swing.

Answer 2

I think they're sending signals to their partner... like where to serve, targeting week players/spots, or something like that.

Answer 3

There's a score board for the points.  They are sending signals - see the site below for some signals commonly used.

Why is it by their butts?  Try signaling behind your back anywhere else: the lower back is the easiest place to reach that both shows the signal to someone behind you and hides it from those in front.

If they happen to have a sponsor's logo on their butt, all the better.